High-speed circuit breaker



Oct. 15 1929. A. J. MOTTLAU 1,731,391

HIGH SPEED CIRCUIT BREAKER Filed. April 50, 1926 2 Sheets-Sheet 1 Li -i WITNESSES: HWENTOR g/Qmw Atgus/ J M017 M M W Mi a 6 ATTORNEY 0a. 15, 1929. A. J. MOTTLAU 1,731,391

HIGH SPEED CIRCUIT BREAKER Filed April so, 19 6 2 Sheets-Sheet 2 I 8 o 1' 3 l2 4 WITNESSES: INVENTOR Patented Oct. 15, 1929 UNITED STATES} PATENT OFFICE AUGUST J. MOTTLAU, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC 8c MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA HIGH-SPEED CIRCUIT BREAKER Application filed April 80,

My invention relates to electrical protective apparatus and particularly to high-speed circuit interrupters.

One object of my invention is to provide a circuit interrupter that shall be held in its closed position only by magnetic forces.

Another object of my invention is to provide a circuit interrupter that shall befree from mechanical tripping latches.

Another object of my invention is to increase the speed of separation of the relatively movable contact members of a circuit interrupter by imparting to one of them a combined turning'and translatory movement.

A further object of my invention is to provide a circuit interrupter that shall be rendered trip-free of its closing mechanism so soon as the holding coil shall have lifted its armature.

In the operation of high speed circuit interrupters, such as operate with a time element of teh one-thousandths of a second or less, it is essential that the moving parts shall be few in number, of relatively light weight and that there shall be no mechanical latching parts, since all of their moments of inertia must be overcome before the circuit interrupter opens. I obtain the desired re sult by moving an armature member into the magnetic field of the holding coil at an angle to its face, thus causing the armature member to turn during its seating movement onto the face of the holding coil, thereby closing the relatively movable contact'members at high speed and rendering the armature member trip-free from the actuating mechanism.

In the accompanying drawings, Fig. 1 is an elvational view, partially in section, of a circuit interrupter embodving my invention in its open position. Fig.2 is an elevational view of my circuit interrupter at the end of the first stage of the closing movement. Fig. 3 is asimilar view at the end of the second stage of the closing movement. Fig.

4 is a similar view of the third or last stage I ports the actuating 1926. Serial No. 105,720.

armature 4 of which is normally supported at an angle to the pole faces of the core 2 by a structure 5. An actuating device 6 is provided for raising the supporting structure 5 in order to permit the closing of a circuit interrupter comprising relatively movable contact members 7 and 8.

In order to secure high speed operation of the circuit interrupter, certain special forms of holding coils are available in which the fluxes are shunted rather than neutralized during the operation of circuit interrupters. The holding coil 2, which is shown diagrammatically may be any of these special forms. For the purpose of the present invention, it is essential that the pole faces of the magnet shall be at an angle to the inoperative position of the face of the armature 4.

The supporting structure 5 comprises a frame 9 of suitable insulating material that slides in suitable guideways 11 carried'by the frame work 1. A frame 9 of upright members is provided with a shaft 12 that constitutes a pivotal support for the armature 4. Depending from the armature 4 is a member 13 of insulating material, having a counter-weight 14, and to the outer end of I\Ovhich is attached the movable contact mem- A downwardly projecting slot of the frame 9, and terminates in a roller 15. A bracket 16 extends outwardly from the frame 9 for supporting the member 13 and armature member 4 in a horizontal position. The center of mass of the armature 4, member. 13, counter-weight 14, movable contact member 8 and roller 15 is preferably arranged to be to the rear of the shaft 12, opposite the contact member 8 in order to cause the inertia of the parts to impart a counter-clockwise turning movement about the shaft 12 when accelerated downwardly. A spring 17 connects the bracket 16 and member 13 to bias the latter into its lower position.

A bracket 18 attached to the frame 1 supdevice 6 that comprises a shaft 19, a cam 21, and an operating handle 22. The contour of the cam 21 mustbe designed with regard to its speed of rotation,

the force of the holding magnet and the moment of inertia of the several parts about the shaft 12. It is to be understood that a motor, gear wheel or any other equivalent form of driving device may be mounted on shaft 19 in lieu of the handle 22. A spring 23 connected to the frame 9 biases the latter moving the frame 9 upwardly against the ten-' sion of the spring 23, until the heel of the armature 4 engages one of the faces of the core 2 which position is shown in Fig. 2.

Referring particularly to Fig. 3, as soon as the armature 4 engages the core 2, the former turns on the shaft 12 into parallelism with the faces of the core 2 which action completes a circuit between the contact members 7 and 8. The closing movement of the armature member 4 also turns the roller 15 about the shaft 12 sufliciently to permit the end of the cam 21 to clear it, thereby rendering the circuit interrupter trip-free so far as the actuating device 6 is concerned. The cam 21 may then be turned to the position shown in Fig. 4.

Upon the occurrence of abnormal circuit conditions such as to de-energize the holding coil 3, the armature member 4 is released and the frame 9 falls under the influence of the force of gravity and by reason of the tension in the spring 23. The roller 15 passes through the circumference of the circle described by the outer point of the cam 21 before the armature member 4 has assumed its horizontal position and engaged the bracket 16.

' as to cause the contact members 7 and 8 to separate w th a turning movement 111 addition to their downward movement of translation.

Accordingly, the circuit interrupter is free to trip open without hindrance from the actuating device 6 so soon as the armature member 4 is drawn from its horizontal position into parallelism with the faces of the core 2. It will thus be seen that I have devised a circuit interrupter that is characterized by having an armature member mechanically moved into the magnetic field of the holding magnet at an angle to the faces of the core. When the armature member is seized by the holding magnet the armature member is turned sufiiciently to render the circuit interrupter trip-free relative to the cam for bringing the armature member into the field of the holding magnet and to close the contact members with a positive movement. The circuit interrupter is free from mechanical latches whereby it depends only upon magnetic forces for holding it in its closed position.

It is to be understood that such changes in the size, arrangement and disposition of the component parts of my invention may be made as fall within the scope of the appended claims.

I claim as my invention:

1. In a circuit controlling device, the combination with a stationary contact member, a holding magnet, an armature therefor and a movable contact member controlled by the armature, of means for actuating the armature into engagement with the holding magnet at an angle to the pole-face thereof, and to render the armature trip-free of the actuating means when the armature is drawn into parallelism with said pole face.

2. In a circuit controlling device, the combination with a stationary contact member, a holding magnet, an armature therefor and a movable contact member controlled by the armature, of means for actuating the armature into engagement with the holding magnet at an angle to the pole-face thereof, comprising members having cooperating surfaces that are moved out of engagement when the armature is drawn into parallelism with the face of the holding magnet.

3. In a circuit controlling device, the combination with a stationary contact member, a holding magnet, an armature therefor and a movable contact member controlled by the armature, of means comprising a pivotal support about which the armature is free to turn for actuating the armature into engagement with the holding magnet at an angle to the pole-face thereof, the holding magnet serving to turn the armature about the said support and into parallelism with said pole face and to thereby render the armature tripfree from a portion of the actuating means.

4. In a circuit controlling device, the combination with a stationary contact member, a holding magnet, an armature therefor and a movable contact'meinber controlled by the armature, of means pivotally supporting the armature and for moving it into engagement with the holding magnet at an angle to the face thereof, and means for actuating the supporting means through engaging surfaces that are rendered trip-free when the armature is drawn into parallelism with the face of the holding magnet.

5. In a circuit controlling device, a stationary contact member, a holding magnet, an

I armature therefor, a movable contact member controlled by the armature, means for pivotally supporting the armature at an angle to the face of the holding magnet, and means for actuating the supporting means, said supporting means being disengaged from the actuating means by the movement of the armature into parallelism with the face of said magnet.

6. In a circuit controlling device, a stationary contact member, a holding magnet, an armature therefor, a movable contact member controlled by the armature, means for pivotally supporting the armature at an angle to the face of the holding magnet the supporting means comprising a member movable with the armature about its pivot, and actuating means for the supporting means engaging the movable member but rendered trip-free therefrom by movement of the armature into parallelism with the face of the holding magnet.

7. In a circuit controlling device, a sta tionary contact member, a holding magnet, an armature therefor, a movable contact member controlled by the armature, means for pivotally supporting the armature at an angle to the face of the holding magnet, the supporting means comprising a roller movable with the armature about its pivot, and actuating means for the supporting means engaging the roller but rendered trip-free therefrom when the armature is drawn into parallelism with the face of the holding magnet.

8. In a circuit controlling device, a pair of relatively movable contact members, a holding magnet, an armature therefor controlling one of the contact members and means for moving the armature into the field of the holding magnet said means being rendered trip-free from the armature by the seizure of the armature member by the holding magnet.

9. In a circuit controlling device, a pair of relatively movable contact members, a holding magnet, an armature therefor controlling one of the contact members and means for moving the armature into the field of the holding magnet said means being trip-free from the armature by the seizure of the armature by the holding magnet, and retrieving means for the armature stressed during the closing movement of the contact members for separating them upon the deenergization of the holding magnet.

10. In a circuit controlling device, a stationary contact member, a holding magnet, an armature therefor, a movable contact member controlled by the armature, means for pivotally supporting the armature at an angle to the face of the magnet, the supportin" means comprising a member movable with the armature about its pivot, actuating means for the supporting means engaging the movable 'member but rendered trip-free therefrom by movement of the armature into parallelism with the face of the holding magnet and retrieving means for the supporting means stressed during the closing movement of the contact members for separating them upon the .de-energi-zation of the holding magnet.

11. Ina circuit controlling device, a statlonary contact member, a stationary magnet, a pivoted armature therefor, a movable con 

